• The Korean Journal of Ecology
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• v.15 no.4
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• pp.329-335
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• 1992

Bionomics of diplopodes was studid near chongyongchi in the chiri mountains from sept. 1990 to dec. 1991 by surveying 10 sample sites at 12 occasions. During this period 13 species of diplopodes from 11 genera, 8 families, and 6 orders were collected. Species were more diversed under quercus mongolica followed by quercus serrata and pinus densiflora sp. epenerchodus koreanus bifidus, and e. k. koreanus were found in all sample sites and these 6 species have been reported to be distributed throughout south korea. yamasinaium sp., riukiaria semicirculalis, parafontaria koreanus, and sicotanus eurygaster were found only under quercus mongolica community and postulated to be related to diet meanwhile other enviromental factors such as temperature, soil ph, and altitude should be taken into consideration. Species diversity index was higher at altitude 700m followed by at 900m, 1, 000m, 800m, 600m, 500m, 1, 100m, 400m, 300m, and 1, 200m in discending order likely due to the enviromental factors such as climatic and edaphic affects, disturbance by human, and degree of floral diversity. Species similarity index was highest 0.78 between altitude 500m and 600m sample sites could be grouped into 3, namely first 300m, 400m, second 500m, 600m, 700m, 1, 000m, 800m, 900m, and third 1, 100m, 1, 200m.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.3
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• pp.188-195
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• 2004

This paper presents neural load torque observer that is used to deadbeat load torque observer and gain compensation by parameter estimator As a result, the response of the PMSM(permanent magnet synchronous motor) follows that nominal plant. The load torque compensation method is composed of a neural deadbeat observer To reduce the noise effect, the post-filter implemented by MA(moving average) process, is adopted. The parameter compensator with RLSM (recursive least square method) parameter estimator is adopted to increase the performance of the load torque observer and main controller The parameter estimator is combined with a high performance neural load torque observer to resolve the problems. The neural network is trained in on-line phases and it is composed by a feed forward recall and error back-propagation training. During the normal operation, the input-output response is sampled and the weighting value is trained multi-times by error back-propagation method at each sample period to accommodate the possible variations in the parameters or load torque. As a result, the proposed control system has a robust and precise system against the load torque and the Parameter variation. A stability and usefulness are verified by computer simulation and experiment.

• Journal of the Society of Naval Architects of Korea
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• v.29 no.3
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• pp.71-79
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• 1992

In order to obtain the wave-making resistance of a ship, so-called the Neumann-Kelvin problem is solved numerically. For computing the Havelock source, which is the Green's function of the problem, we adopted the methods given by Newman(1987) for the term representing the local disturbance, and Baar and Price(1988) for the wave disturbance, respectively. In the numerical code we developed, the source strength is assumed as bilinear on each panel and continuous throughout the hull surface. The wave-making resistance is calculated using the algorithm of de Sendagorta and erases(1988), which makes use of the wave amplitude far downstream. The Wigley hull was chosen for the sample calculation, and our results showed a good agreement with other existing experimental and numerical results.

• Journal of the Korean Geotechnical Society
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• v.23 no.12
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• pp.95-107
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• 2007

This study describes compressive characteristics of marine clay at southwestern coast in Korea by large block and piston samples. Through the analysis of disturbance effect and various consolidation test, consolidation result shows that volumetric strain from large block samples is lower than piston samples and compression index of large block samples is larger than piston samples value. We suggest new empirical equation of compression index by the effect of compression index following sampling method. If consolidation settlement is presumed using empirical equation of compression index, the resort will be more reasonable in predicting settlement than that obtained by the decision of compressibility characteristics from piston samples.

• Korean Journal of Environment and Ecology
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• v.22 no.5
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• pp.505-513
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• 2008

The purpose of this study is to analyze the distribution patterns and characteristics of plant species by human impact in urban areas. In order to achieve a comprehensive data acquisition of all autogenously introduced vascular plant species occurring in the city of Cheon-ju, this study made an analysis of 106 sample plots, each with a size of one hectare, These sample plots were selected to represent the typical land-use patterns within the city of Cheon-ju and to cover the various distances from the city center. Species richness, patterns of life forms, and the percentage of non-native species were analyzed in relation to the degree of hemeroby of the sample plots. It was found that the species number appeared the largest in sites that were moderately influenced. This result corresponds to the intermediate disturbance hypothesis that moderate disturbance leads to an increase in species richness. The flora of sites which were subject to the highest level of human impact, was characterized by a high proportion of annual species and non-native species. In addition, some species were divided into three groups with similar distribution corresponding to land-use type and urban zone: urbanophobic (e.g. Indigofera kirilowii, Prunus sargentii, Rhus trichocarpa), urbanoneutral (e.g. Commelina communis, Erigeron annuus, Metaplexis japonica) and urbanophilus (e.g. Euphorbia supina, Senecio vulgaris, Taraxacum officinale).

• Journal of the Korean Geotechnical Society
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• v.19 no.1
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• pp.93-102
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• 2003

Unconfined compression test (UC) has been widely used to determine the undrained shear strength ($c_u$) of clay, because it is convenient and economical. However, UC can not represent the behaviour of in-situ stress condition and the strength obtained by the test is generally underestimated compared to that of triaxial compression, due to no confining pressure. Therefore, a simple and practical method to correct the ($c_u$) for sample disturbance and to be used in geotechnical practice is needed. This study is aimed at proposing the method to estimate in-situ undrained shear strength from UC with suction measurement. The proposed method is based on theoretical shear strength equation of perfect sample (Noorany & Seed, 1965), and effective overburden stress and analysis results ($A_f,\phi'$) of effective stress behaviour by UC are needed for the equation. The shear resistance angle ($\phi'$) can be simply estimated through the result that $K_f$-line slope of the UC is 1.6 times higher than that of triaxial compression test. The result of this study shows that the measured strength by this method is very similar to that of the undrained shear strength by triaxial compression test (CK$_0$UC).

• Applied Chemistry for Engineering
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• v.2 no.4
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• pp.393-398
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• 1991

An experimental reactor system was devised and employed to examine catalytic coal gasification. A 4-kw tungsten halogen lamp heater combinded with a graphite sample basket coated with silicon nitride film made rapid heating and cooling possible. Also a small graphite cap on the thermocouple tip which located just beneath the sample basket helped remarkably to read real temperatures. Silicon nitride film on the basket and the cap showed very good protection against the reaction between graphite and oxidant gases during the experiments. The weight of specimen could be continuously measured without disturbance.

• Journal of the korean society of oceanography
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• v.38 no.4
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• pp.166-172
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• 2003

Multi­Sensor Core Logger (MSCL) is a useful system for logging the physical properties (compressional wave velocity, wet bulk density, fractional porosity, magnetic susceptibility and/or natural gamma radiation) of marine sediments through scanning of whole cores in a nondestructive fashion. But MSCL has a number of problems that can lead to spurious results depending on the various factors such as core slumping, gas expansion, mechanical stretching, and the thickness variation of core liner and sediment. For the verification of MSCL data, compressional wave velocity, wet bulk density, and porosity were measured on discrete samples by Hamilton Frame and Gravimetric method, respectively. Acoustic impedance was also calculated. Physical property data (velocity, wet bulk density, and impedance) logged by MSCL were slightly larger than those of discrete sample, and porosity is reverse. Average difference between MSCL and discrete sample at both sites is relatively small such as 22­24 m/s in velocity, $0.02­-0.08\;g/\textrm{cm}^3$ in wet bulk density, and 2.5­2.7% in porosity. The values also show systematic variation with sediment depth. A variety of factors are probably responsible for the differences including instrument error, various measurement method, sediment disturbance, and accuracy of calibration. Therefore, MSCL can be effectively used to collect physical property data with high resolution and quality, if the calibration is accurately completed.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.1
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• pp.95-104
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• 2020

The purpose of this study is to develop a pipe type soil sampler that can easily collect soil cross section servey and soil samples to conduct ecological environment surveys while minimizing ecological disturbance in the area subject to soil survey. Furthermore, this study develop the exponential type estimation specific weight formula (ESWF) that uses pipe type soil sampler to easily carry out soil cross section survey and soil sample while estimating the specific weight of the area using water content and soil sample length variation ratio (SLVRs) and to obtain apparent specific gravity, hardness, and max. porosity which are used as growth of corps and ecological environment index. The calibration results of ESWF showed a high degree of significance, with NSE for actual specific weight (γ₀) and calibration estimation specific weight (γ_ec) 0.95, R² for 0.954, and RMSE for 0.051. The verification results of ESWF showed a high significance, with NSE for actual specific weight (γ₀) and verification estimation specific weight (γ_ev) 0.881, R² for 0.978, and RMSE for 0.055.

• Journal of Oriental Neuropsychiatry
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• v.2 no.1
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• pp.94-107
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• 1991

This clinical study was done to investigate how the perticular elements of coffee reflects a person using MMPI (Minesota Multiphasic Personality Inventory) as a guide. This study was done based on the sample groups of 29 coffee-drinking-studensts and 21 non-coffee-drinking students. The results were as follows ; 1. The mean T-scores on all the scales were within normal range in coffee-drinking-group. 2. The personal traits of coffee-drinking-group showed elevated scales of Hs, D, Hy and Pt and showed 3, 1, 2 profile type. 3. Comparing non-coffee-drinking-group with coffee-drinking-group, scales of Hs, D, Hy, Mf, Pt, Ma were significantly higher in the latter. 4. According to pattern analysis, Psycho-neurotic trait was recognized in 62.07% of non-coffee-drinking-group, 76.19% of coffee-drinking-group. As a result, aboves support the exiting hypothesis that coffee give rise to Blood-asthenia(血虛) and Spleen-Lack of transports(脾不運化) and have an influence on neurosis, psychosis and sleep disturbance.